In addition to white and red blood cells, blood plasma, there is another group of elements - platelets. Their main function (in addition to the transfer of nutrients) - monitoring the state of general circulatory system and its recovery in case of violation of the integrity of the vessel walls. These corpuscles order of magnitude less than other elements. Their size reaches just 4 microns, and life expectancy of platelets is 7-9 days.
where form
The small amount of platelets originate in the lungs. But the majority is in the bone marrow is red, which contains large cells called megakaryocytes. Their size comes to 115 microns. These giant cells and produce platelets, which are dropped from the mother source, fall in blood plasma and spread it throughout the human body.
In normal operation, such a bone marrow cell produces approximately 3,000 cells. In the case of trauma and blood loss increases platelet production by 15-20 times. Their main part of the liquid contained in the blood, and about 30-35% accumulates in the spleen, forming a reserve in case of emergency.
Platelets are disk lenticular shape without core and saturated projecting receptors which instantly react to vascular injury of the epithelium. Having received such a signal, they massively rush to damage his body close it and form a clot prevents blood leakage and the ingress of harmful elements in the body from outside.
how many live
In medicine taken to calculate the life cycle of these cells after being deposited in the blood fluid. By the time the average duration of stay of platelets in the bloodstream - a week and a half. Its function - providing normal operation of blood vessels and to prevent blood loss - they operate equally well regardless of in what stage.
During this period, you can watch them in three stages:
- Emerging and gaining activity. They are sized slightly larger than the other.
- Active.
- Loses its functionality. Marked thinning and formation of a whitish rim around the cell body.
What affects the life span
The duration of life of platelets in human blood is dependent on the presence of various pathologies (open wounds, internal and external bleeding and so on. D.). Protective corpuscles accumulate and create a cluster at sites of inflammation or vascular lesions and skin.
They are deformed to form a platelet plug and release substances required for regeneration of tissues. Tau can independently destroy harmful bacteria and substances trapped in the body. They capture and neutralize them, but they can be lost.
Platelets are activated by raising the concentration of epinephrine in the body or the affected site. On the duration of their life can influence the psycho-emotional state of a person, such as stress and physical exertion. Alcohol negatively affects their development and strength.
In medicine, the general condition of the person and his presence of any disease is evaluated by the number of platelets in the blood. Changing the size and period of the life of these elements is determined by a specialist for each person individually and in combination with other indicators.
This value may be overstated or understated compared with the norm, which varies depending on the person's age and gender.
For example, women have an increased production of these cells during menstruation and gestation.
Reducing the number of blood platelets - thrombocytopenia. It can occur when infectious infections, blood diseases, disorders of the bone marrow or kidney. There are medications that reduce their content in the blood fluid.
Raising these elements - thrombocytosis. He points to a reinforced bone marrow job starting in the presence of cirrhosis, tuberculosis, oncology.
How to die
Mitochondrial necrosis - a condition in which the death of cells occurs during their excessive activation. To go into this state, platelets need to change the calcium concentration in the cytoplasm. With an increase in its amount to excess cell skeleton is destroyed.
In all living cells, the mitochondria are present, which provide energy resulting from oxidation-reduction reactions. They have inside and platelets. During activation of mitochondria cells capture and retain calcium.
With the accumulation of its concentration becomes higher than normal, protective calf cell envelope expands and collapses (micro explosion), destroying all harmful elements penetrated into the patient. Because of this, for platelets stuck the name "cell suicide."
Disposal of platelets after the term ended their productive function, occurs in the spleen and liver. These bodies are destroyed there are macrophages present in separate elements which are then used by the body to form a variety of organs.
